Abstract

High performance InGaAsP/InP multiquantum well (MQW) buried heterostructure lasers emitting around 1.3 μm were prepared for the first time by chemical‐beam epitaxy. At 20 °C, continuous‐wave (cw) threshold currents were 5–8 mA and quantum efficiencies were 0.35–0.45 mW/mA for 250 μm long lasers having one facet ∼85% reflective coated. At 80 °C, the cw threshold currents remained low, 23 mA, quantum efficiency stayed high, 0.22 mW/mA, and output power of ∼10 mW was achieved. cw power output as high as 125 mW was achieved with 750 μm long lasers having AR–HR (∼5%–85%) coatings. Lasers with bulk active were also studied for comparison. Though they also have excellent device performance, in general, they are somewhat inferior to MQW lasers.